Appendix C - Code Reuse - Program Templates - Code Snippets - Code Templates

1. Appendix C - Code Reuse - Program Templates - Code Snippets - Code Templates

2. Reusable Source Code – Snippets and Templates Reusing code has been a "holy grail" of software development for decades. While there is no silver bullet solution, there are a number of innovative and useful options in RDz for this: • Program Templates • Code Snippets • Code Templates We've already seen in previous slides that you can create new programs using templates, which allows you to create and enforce standards, and simplify development. Snippets allow you to create smaller, "packets" of reusable code – from single statements to routines. We'll first look at customizing the program templates: To access their defaults: From Window > Preferences > COBOL > Code Templates

3. Creating New Programs Using Templates • There are several ways to create new programs from scratch • The "Best Practice" method is to use RDz's COBOL program templates From File, New > Other… …in the Wizards panel, - Type: cobol - Select COBOL Program - Click Next > …in the COBOL Program panel, - Name the Program - Click Next > • Finally you specify which folder to create the program: • Select the cobol folder • Click Next > Note – You can create new programs

4. Creating New Programs From Templates – continued You can add CICS or DB2 template sample code to your new program: • Check the features you'd like • Click Finish • A few things happen: • Your new program is created  • The Snippets view is opened • Snippets information can be found in Appendix B of these slides Note that you can customize the templates used to create new programs From Window, Preferences, select: COBOL • Code Templates • Features

5. OPTIONAL TOPIC – Create New Program in a z/OS LPAR • You can create new programs using the New COBOL Program wizard, provided you are connected to a z/OS LPAR, and that you have created a z/OS Project/MVS Subproject (see Location: in the screen capture below). MVS SubProjects and z/OS Projects are covered in another module of this course

6. Customize the New Program Templates – Comments You can create a custom Code Template for COBOL comments or the base program code itself. To add or customize comments: • Click the comment option you wish to modify • Code an asterisk in position 7 (you'll have to space over 1-6) • You can insert Variables that are filled in when new "templatized" programs are created

7. Customize the New Program Templates – Program Code And you can add your own entries, common files, databases, variables, routines etc. to either: • An entire program • Separate program divisions When a new program is created using the templates all of the custom comments and code are inserted.

8. Code Snippets Sometimes, instead of entire programs you might want to: • Save some code temporarily for reuse – similar to the ISPF: "CREATE" and "COPY" command line commands • Create a paragraph, computation, complex conditional – that can be re-purposed in other programs • Provide a library "standard" routines – using your shop's coding conventions • Provide a library of syntactically-correct and infrequently used/high-value statements: • Job Cards • Database routines • Complex COBOL code: UNSTRING etc. Snippets are the preferred way of doing this. You access them through a Snippets view, which you get to by: • From Window > Show View > other… • Type: snippets – and select the Snippets view On the right are a group of custom Snippets that we have created. You will see a subset of these in your workspace. Individual Snippets are contained in "drawers" which are the accordion menus that collapse/expand on-click. Snippets can be Exported and Imported (for sharing)

9. Using Code Snippets (ISPF "COPY" command line command) To use an existing code Snippet follow the steps below: • Place your cursor at the exact focal point (position in the source) where you want a code snippet inserted • Find your Code Snippet in the snippet drawers • Double-Click the Snippet • If there are variables in the snippet, you can: • Accept the defaults • Over-ride the values before the code is inserted • Click Insert

10. Creating Code Snippets (ISPF "CREATE" command) – 1 of 2 To create a new code Snippet follow the steps below: • Create a new Snippet category • Right-click over the Snippets view • Select Customize • From Customize Palette, under New Select: New Category • Name the Category • Add a description • Click OK • Select and copy the code you wish to Snippet-ify  • Expand the category you wish to add the Snippet to, and select Paste as Snippet…

11. Creating Code Snippets (ISPF "CREATE" command) – 2 of 2 4. Rename the Snippet and give it a Description 5. Optionally add Variables to be filled in by Snippet users (or they can accept the defaults)

12. Using a Code Snippet for a Job Card In ISPF you might use the ISPF command line COPY command to insert a Job Card into a JCL deck. Let's try this with RDz • From the \ jcl \ folder, open: BR14.jcl • Select and Cut (Ctrl+X) the Job card • From the Snippets view, double-click: JOB Card • Enter a new JobName and a new MsgClass value • Click OK and verify your work

13. Using Code Snippets as a Scratch Pad Area for Multiple Paste Buffers Occasionally you may need to create multiple “copy/paste buffers” – if you need to say, replicate a set of changes across multiple programs. This can be accomplished using Snippets: • Open a program • Copy and create a Snippet from a code fragment • Optionally customize the Snippet to include Variables – for generalized use • Create another Snippet • Repeat from step 1 until you’ve created separate Snippets for each code fragment • Apply the Snippets to your program(s) • Optionally Export the Snippets to other developers on your team

14. The IMS Code Snippets If you are using RDz v7.6 or later, a number of very useful IMS Code Snippets are shipped with the product  These snippets go beyond simple text-based insertion to read your Data Division entries, and offer options for building statements using combo-boxes

15. RDz's Customize-able Content Assist Templates • Finally - you can customize RDz's template "proposals" offered in the Content Assist • You access this from: • Window • Preferences • COBOL • Templates • Customization options include: • Modify (Edit…) an existing template • Add a (New…) template • Remove a template • Export all templates – so that other team members can share • Import… • Restore Removed (un-delete) • Revert to Default (un-modify) • You can customize a template's: • - Content - Pattern - Context - where it's applicable - Description – hover help

16. OPTIONALWorkshop – Customizing Template Proposals • From Window, Preferences, COBOL, Templates: • Select one of the Template proposals and delete (Remove…) it • Select a Template proposal and Edit… (change it) – something simple like changing the case to mixed-case, instead of all UPPER case • Add a New… proposal, as shown here  You can copy and paste the this text. If <condition one> Then If <condition two> <imperative statements on true path> Else <imperative statements on inner false path> Else <imperative statements on outer false path>. • Test your work out in one of the sample programs, like: PATLIST.cbl

17. Code Reuse – Summary • Three methods of Code Reuse: 1. Program Templates • Useful if creating a new COBOL or PL/I program using the New program wizard • Can include standard (not customized) minimal CICS and SQL statements 2. Snippets • Most flexible and simple method of code reuse • Snippet scope can be from anywhere from a keyword to an entire program • Can define any number of custom variables to manage idiosyncratic requirements • Can export/import Snippets with Workspace • Can include Snippets view in custom Perspective 3. Code Templates • Most granular form of code reuse • Integrates with Content Assist • Typically used for statements – but could extend to more code (just, the interface is a little unwieldy)